82 lines
2.1 KiB
C
82 lines
2.1 KiB
C
/* Decoder Core for OpenPICC
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* (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <errno.h>
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#include <sys/types.h>
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#include "openpicc.h"
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#include "dbgu.h"
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#include "decoder.h"
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static struct decoder_algo *decoder_algo[DECODER_NUM_ALGOS];
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static int get_next_data(struct decoder_state *st, u_int8_t *data)
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{
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u_int8_t parity_sample;
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u_int32_t bytesample;
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bytesample = st->algo->get_next_bytesample(st, &parity_sample);
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return st->algo->decode_sample(bytesample, data);
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}
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/* iterate over sample buffer (size N bytes) and decode data */
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int decoder_decode(u_int8_t algo, const char *sample_buf,
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int sample_buf_size, unsigned char *data_buf)
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{
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int i, ret;
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struct decoder_state st;
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if (algo >= DECODER_NUM_ALGOS)
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return -EINVAL;
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st.buf = sample_buf;
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st.buf32 = (u_int32_t *) st.buf;
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st.bit_ofs = 0;
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st.algo = decoder_algo[algo];
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for (i = 0; i < (sample_buf_size*8)/st.algo->bits_per_sampled_char;
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i++) {
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ret = get_next_data(&st, &data_buf[i]);
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if (ret < 0) {
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DEBUGPCR("decoder error %d at data byte %u",
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ret, i);
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return ret;
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}
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}
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return i+1;
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}
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int decoder_register(int algnum, struct decoder_algo *algo)
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{
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if (algnum >= DECODER_NUM_ALGOS)
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return -EINVAL;
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decoder_algo[algnum] = algo;
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return 0;
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}
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void decoder_init(void)
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{
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decoder_register(DECODER_MILLER, &miller_decoder);
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decoder_register(DECODER_NRZL, &nrzl_decoder);
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}
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